To communicate between one another and/or with a terrestrial station, satellites use microwave beams that are formed and received by means of antennas that include reflectors of large size. Efficient focusing of the telecommunications beam is obtained solely by reflection on a surface of the reflector whose deviations from a desired ideal surface are small relative to the wavelengths used. A deviation of a part of the real surface of the reflector from the ideal surface (e.g. a paraboloid of revolution) gives rise to a phase shift in the signal reflected by that region in comparison with the signal that would have been reflected by the ideal surface.
Firstly, forming of a narrow beam and/or reception of a maximum amount of energy from a beam requires antennas of large aperture.
Secondly, placing a satellite and its antenna into orbit is facilitated by the antenna reflector being compact when in a folded condition during launch, and also by the reflector being low in mass.
Various solutions have been proposed for making such reflectors, and in particular reflectors that include a reflecting membrane tensioned over a frame.
None of the reflectors presently in service or proposed provides satisfaction simultaneously on all of the points mentioned above.